With men, the state of nature is not a state of peace, but war.

The busier we are, the more acutely we feel that we live, the more conscious we are of life.

A science of all these possible kinds of space [the higher dimensional ones] would undoubtedly be the highest enterprise which a finite understanding could undertake in the field of geometry... If it is possible that there could be regions with other dimensions, it is very likely that God has somewhere brought them into being.

There will always be some people who think for themselves, even among the self-appointed guardians of the great mass who, after having thrown off the yoke of immaturity themselves, will spread about them the spirit of a reasonable estimate of their own value and of the need for every man to think for himself.

Two things strike me dumb: the infinite starry heavens, and the sense of right and wrong in man.

It is therefore correct to say that the senses do not err — not because they always judge rightly, but because they do not judge at all.

I have no knowledge of myself as I am, but merely as I appear to myself.